1991-2020 Degrees Fahrenheit 1 72.0 73.9 -1.9 30 46 1976 2020 1951 1953 normal 2 70.9 71.9 -1.0 43 32 1972 1991 1951 1953 normal 1966,1989,1997 3 65.7 68.4 -2.7 20 55 1961 1991 1950 1953 bottom-third 1980 4 62.6 64.0 -1.4 32 43 1961 1991 1953 1952 normal 1981,1985,1994,2000 5 56.7 59.0 -2.3 21 54 1950 2012 1951 1953 bottom-third 1963 6 52.8 54.2 -1.4 36 39 1978 2012 1953 1953 normal 1953,1985,2008 7 49.2 50.5 -1.3 39 36 1978 2012 1951 1953 normal 1964,1993,2009 8 47.0 48.3 -1.3 35 40 1978 2012 1951 1953 normal 1955,2009 9 46.4 47.7 -1.3 39 35 1978 2012 1952 1953 normal 10 47.3 48.3 -1.0 44 30 1978 2012 1953 1949 normal 1985 11 48.8 49.9 -1.1 45 29 1978 2012 1953 1949 normal 12 50.7 51.7 -1.0 45 29 1978 2012 1953 1949 normal 1976,1992 18 51.4 52.5 -1.1 43 30 1979 2012,2017 1953 1954 normal 24 50.5 51.6 -1.1 43 29 1978 2017 1953 1950 normal 1955,1989,2004 36 50.2 51.6 -1.4 32 38 1979 2018 1953 1954 normal 1995 48 49.7 51.5 -1.8 22 46 1980 2019 1953 1952 bottom-third 1952,1973 60 49.6 51.5 -1.9 22 44 1981 2020 1954 1953 bottom-third